Ductless vent fans...

I have a really small bath in my basement and it has not exhaust fan. It gets pretty steamy in there when you shower. I usually just turn on a fan on the floor when I'm done to get some air circulating.

I was considering putting in an exhaust fan when I ran across an add for a "ductless" vent fan. It recirculates the air in the room and filters it through a charcoal filter of some kind.

It would help if someone took a big smelly dump, but as to removing moisture...no way. The only way to get rid of that is to either run a dehumidifier or exhaust it. It wouldn't do much for the smell either once the charcoal filter was saturated, either. Almost as useless as a ventless stove hood. That will trap some of the grease and smoke, but blows the rest around the kitchen. Much better to dump it outside in both cases.

Thanks you guys. That's definitely the consensus. Guess I'll be drilling through my exterior brick. I can't understand why it was installed without one. Would've been so much easier to do then than now.

Maybe the basement bath was an unpermitted add-on? Very unusual in my limited experience for a building official to allow an unvented bath (a window usually qualifies). You should be able to get away with just a 4 1/8" hole in the wall, though. Do the joists run to the wall or parallel to it?

There is already a light installed and that joist is a channel running to the exterior wall. The tricky thing is that I'd need to cut away the celing in the shower (which Is greenboard) to get access to the wall I'd need to drill. Or I suppose if I could figure out where the drill the hole from outside of the house I could make the hole, and slide the ducting and the vent in from the outside, then hook up to the fan.

If the shower is on the outside wall, then you've only got a short distance to the wall, which will make things easier. Since the fan housing will require a pretty good-sized hole, you'l have plenty of room to work overhead. I'd make the best measurement I could, then drill a small (1/4" or so) hole from the outside and see where it came out. Adjust as necessary, then drill for effect with whatever it will take to run the duct and outside weather cap, flapper, etc. You'll want the outside piece to end close enough to work on from the fan-hole, so you can connect a flexible duct from the fan to the outside duct.

It's best to avoid flexible ductwork when possible, especially for longer runs. It adds friction and decreases the efficiency of the fan. This is especially true for dryer vents - in that case, it ends up costing you money as lint gets caught in the folds, slows the airflow, and becomes a fire hazard as well. If you use solid wall ductwork, you might want to consider making sure it slopes downward towards the outside. Any condensation that occurs would drain out rather than rain back down on you while standing under the intake. You might look into a fan motor that is designed to sit on the outside wall. It would be quieter. Haven't looked for one for a bathroom, but someone probably makes one. They are available for stoves, though.